Tetrakisazo dyes



Ilnited States Patent 3,350,383 TETRAKISAZO DYES Charles L. Conway, Lock Haven, Pa., assignor to American Aniline Products, Inc., a corporation of Delaware No Drawing. Filed Nov. 3, 1964, Ser. No. 408,666 5 Claims. (Cl. 260-166) This invention relates to tetrakisazo dyes. In one specific aspect it relates to tetrakisazo dyes, made using resorcinol as a coupling component, which are remarkably useful for coloring rigid and non-rigid plastics and which are also suitable for coloring petroleum hydrocarbons.

Disazo and trisazo derivatives of resorcinol are not new. Orndorlf and Ray in the American Chemical Journal, volume 44 (1910), report disazo derivatives made by coupling two moles of diazotized 0- or p-toluidine into resorcinol and three moles of diazotized o-toluidine into resorcinol to give the 2,4,6-triazo-substituted derivative.

ful as good plastic colors I have discovered a new class of tetrakisazo dyes made from resorcinol which are unexpectedly good plastic colors and are characterized by remarkable lightfastness.

particularly useful as colorants for rigid and non-rigid plastics because of their good solubility in plastics and excellent lightfastness, and which are also useful as oil colors.

In accordance with the invention I have discovered new dyes of the formula:

In the above formula n is an integer having a value of 45 cent o-toluidine and mole 1-2. R 1s a member selected from the group consisting group consisting of hydrogen, methoxy, and alkyl radicals having from 1-4 carbon atoms, at least one R being a substituent other than hydrogen.

The aminoazo intermediate is diazotized in the usual way by heating it in a concentrated solution of a strong mineral acid, such as hydrochloric acid, cooling the mix- C. and adding thereto a quantity of sodium nitrite slightly in excess of the stoisulfuric acid by heating at a 70 C., cooling the resulting solution to 0-10 C. and adding thereto the aminoazo intermediate.

The tetrakisazo dyestuff of charged 44 g. (0.2 mole) of an Oil Red Base (prepared by diazotizing and coupling a mixture of mole perpercent mixed xylidines), 300 g. water and 60 g. of 20 Baum hydrochloric acid. The mixture was stirred for 12 hours at 25-30 C. and then iced to 0 C. At 0-10 C. there was added 14.1 g. of sodium nitrite as a 20 percent solution. The reaction mixture was maintained at 0-1 C. for three hours, during which time it was tested for acidity to Congo Red and for the presence of an excess of nitrous acid.

To a two-liter beaker equipped with agitator there was separately charged 11 g. resorcinol (0.1 mole), 200 g. water, 80 g. sodium hydroxide percent), and 28 g. sodium carbonate. The resulting coupling solution was iced to 0 C. and the separately prepared diazonium solution was added thereto. The mixture was stirred overnight at 20-25 C. then filtered and washed alkaline free to Brilliant Yell-ow paper with cold water. The product was dried in an oven at 80-90 C. to give 52.4 g. of pure color.

Example 11 Examlple III To a one-liter beaker equipped with agitator there was charged 51.0 g. (0.2 mole) of an Oil Red Base (prepared by diazotizing and coupling o-ethylaniline), 300 g. water was stirred for 12 hours at 25- 30 C. and then iced to as a 20 percent solution. The reaction mixture was mainb 3,350,383 3 4.- and 60.0 g. of 20 Baum hydrochloric acid. The mixture Example V To a one-liter beaker equipped with agitator there was charged 51.2 g. (0.2 mole) of an Oil Red Base (prepared tained at 0l0 C. for three hours, during which tim y dlazotlzmg and couphng 50 mole percent 0 at yl 6 it aniline and 50 mole ercent o-anisidine 300 water was tested for acidity to Congo Red and for the presence and 60 of Baurn hydrochloric g a Thegmixtum of an excess nitrous was stirred for 12 hours at 25-30" C. and then iced to 0 To a two-liter beaker equipped with agitator there was At C. there was added 141 g. of Sodium Separately g f 11 if g mole) nitrite as a 20 percent solution. The reaction mixture was Water 80 8 mm by tom 6 (1 0 Percent) and 10 maintained at 010 C. for three hours, during which @35 z f g 3: resultmtgl coupling 5 time it was tested for acidity to Congo Red and for the 1c 0 an e Separa 6 Y Prepare lazomum presence of an excess of nitrous acid.

iiiiiii $352? 1 11331323 fiifi viisilii 233E335; 1355;egg;g f gg g g gge gjgg g gg is.fallzrtnirarzatse 2 3. 2:33:; 15 80 we e 28 sodium carbonate. The resulting coupling solution was color iced to 0 C. and the separately prepared diazonium Example I V solution was added thereto. The mixture was stirred over- To a one-liter beaker equipped with agitator there was night at -25 C. then filtered and washed alkaline free charged 51.4 g. (0.2 mole) of an Oil Red Base (prepared 20 to Brilliant Yellow paper with cold Water. The product C. At 0l0 C. there was added 14.1 g. of sodium nitrite by diazotizing and coupling 50 mole percent mixed was dried in an oven at 8090 C. to give 64.0 g. of pure xylidines and 50 mole percent o-anisidine), 300 g. water color. and 60.0 g. of 20 Baum hydrochloric acid. The mixture The dyes of Examples III, IV and V, when tested in was stirred for 12 hours at -30 C. and then iced to methyl methacrylate molding powder, give results sub- 0 C. At 0-10 C. there was added 14.1 g. of sodium 25 stantially similar to that of Example II.

nitrite as a 20 percent solution. The reaction mixture was I claim:

maintained at 010 C. for three hours, during which 1. A compound of the formula:

HO OH time it was tested for acidity to Congo Red and for the wherein n is an integer having a value of 1-2; R is a presence of an excess of nitrous acid. 4 member selected from the group consisting of hydrogen To a two-liter beaker equipped with agitator there was and alkyl radicals having from 1-4 carbon atoms, at

separately charged 11 g. resorcinol (0.1 mole), 200 g. least one Ron each benzene ring being an alkyl radical water, 80 g. sodium hydroxide (100 percent), and 28 g. having from l-4 carbon atoms; and R is a member sodium carbonate. The resulting coupling solution was selected from the group consisting of hydrogen, methoxy iced to 0 C. and the separately prepared diazonium and alkyl radicals having from 14 carbon atoms, at least solution was added thereto. The mixture was stirred overone R being a substituent other than hydrogen. night at 2025 C. then filtered and washed alkaline free 2.

C H C H OH OH m-15 OOH OH on was dried in-an oven at 8090 C. to give 63.0 g. of

pure color,

References Cited UNITED STATES PATENTS 2,535,416 12/1950 Hinderrnann et a1.

CHARLES B. PARKER, Primary Examiner. DONALD M. PAPUGA, Assistant Examiner. 

1. A COMPOUND OF THE FORMULA: 